He passed away Tuesday morning at the age of 98, his daughter Katherine confirmed to The New York Times. His acting career spanned more than 60 years and included roles alongside Marilyn Monroe and Clark Gable (in 1961's The Misfits) as well as playing the villain opposite Clint Eastwood (in the 1966 Western, The Good, the Bad and the Ugly).

Other memorable roles include his portrayal as a mafia don in 1990's The Godfather Part III, and in 2006, playing Kate Winslet's unlikely BFF in The Holiday. (You might remember when he told her, "You, I can tell, are a leading lady, but for some reason you are behaving like the best friend.")

He continued working in film into his 90s, which included roles in Roman Polanski's 2010 film Ghost Writer and in the same year, Wall Street: Money Never Sleeps.

Much of Wallach's work in film was critically acclaimed, but he never earned an Academy Award nomination. He did, however, earn an honorary Oscar in November 2010—less than a month before his 95th birthday.

What Wallach really loved was theater, and as he explained to the New York Times in 1973, "For actors, movies are a means to the end."

"I go and get on a horse in Spain for 10 weeks, and I have enough cushion to come back and do a play," he said. He made his Broadway debut in 1945, and three years later, married fellow theater star Anne Jackson. The pair had three children together and were married for 66 years, up until his death.

The couple frequently worked together, but as Jackson told The Hartford Courant in 2000, they were "not the couple we play onstage," explaining, "For us, it's fun to separate the two."

And it stayed fun fort Wallach! In a 1997 interview with The New York Times, Wallach, a founding member of the acclaimed Actors' Studio, explained why he kept kept working all those years. "What else am I going to do?" he asked. "I love to act."